Yoon Ji Hoon is a genius forensic doctor of the National Scientific, Criminal & Investigation Laboratory

Kim Ah Joong - Ko Da Kyung
Ko Da Kyung is a rookie forensic doctor of the National Scientific, Criminal & Investigation Laboratory. She makes career change after working in the coroner's office.

Jung Kyu Woon - Choi Yi Han
Choi Yi Han is a hot-blooded cop working in the violent crimes division

Uhm Ji Won - Jung Woo Jin
Jung Woo Jin is a successful, smart prosecutor who apparently views the doctors’ work as merely one tool for HER to use.

Jun Kwang Ryul - Lee Myung Han
Director of the National Scientific, Criminal & Investigation Laboratory